Labor Day weekend officially signals the close of the Summer box office season, and this year's ended on, as Variety described it, "a whimper" as opposed to a bang. Tropic Thunder landed in the top spot for the third weekend in a row, pulling in an estimated $14.3 million over four days. The second spot went to Babylon A.D. which earned an estimated $12 million. The Dark Knight came in at No. Read more